Copper Deficiency and Elastin Metabolism in Avian Lung

Copper deficiency in the chick causes anatomical changes in lung that are characterized by an apparent thinning of the air-blood capillary network of tertiary bronchi. Although the net content of the elastin in lung was not changed significantly by nutritional copper deficiency, it was possible to demonstrate an increase in the lysine content and a decrease in the desmosine content of lung elastin from copper-deficient chicks compared to that from controls. Further, the content of soluble elastin was also increased two- to fourfold in lung from copper-deficient chicks. Subsequently, nutritional copper deficiency was used to facilitate the isolation of chick lung tropoelastin. This lung protein appeared to be similar in selected properties to tropoelastin isolated from aorta of copper-deficient chicks. In addition, data are presented that indicate elastin in avian lung is possibly subject to only limited turnover.